/**
 * 内外旋轮曲线
 * @module zrender/shape/Trochold
 * @author Neil (杨骥, 511415343@qq.com)
 * @example
 *     var Trochold = require('zrender/shape/Trochold');
 *     var shape = new Trochold({
 *         style: {
 *             x: 100,
 *             y: 100,
 *             r: 50,
 *             r0: 30,
 *             d: 50,
 *             strokeColor: '#eee',
 *             text: 'trochold'
 *         }
 *     });
 *     zr.addShape(shape);
 */
/**
 * @typedef {Object} ITrocholdStyle
 * @property {number} x 中心x坐标
 * @property {number} y 中心y坐标
 * @property {number} r 固定圆半径 内旋曲线时必须大于转动圆半径
 * @property {number} r0 转动圆半径
 * @property {number} d 点到内部转动圆的距离，等于r时曲线为摆线
 * @property {string} [location='in'] 内旋 out 外旋
 * @property {string} [strokeColor='#000000'] 描边颜色
 * @property {string} [lineCape='butt'] 线帽样式，可以是 butt, round, square
 * @property {number} [lineWidth=1] 描边宽度
 * @property {number} [opacity=1] 绘制透明度
 * @property {number} [shadowBlur=0] 阴影模糊度，大于0有效
 * @property {string} [shadowColor='#000000'] 阴影颜色
 * @property {number} [shadowOffsetX=0] 阴影横向偏移
 * @property {number} [shadowOffsetY=0] 阴影纵向偏移
 * @property {string} [text] 图形中的附加文本
 * @property {string} [textColor='#000000'] 文本颜色
 * @property {string} [textFont] 附加文本样式，eg:'bold 18px verdana'
 * @property {string} [textPosition='end'] 附加文本位置, 可以是 inside, left, right, top, bottom
 * @property {string} [textAlign] 默认根据textPosition自动设置，附加文本水平对齐。
 *                                可以是start, end, left, right, center
 * @property {string} [textBaseline] 默认根据textPosition自动设置，附加文本垂直对齐。
 *                                可以是top, bottom, middle, alphabetic, hanging, ideographic
 */


var Base = require('./Base');
/**
         * @alias module:zrender/shape/Trochold
         * @param {Object} options
         * @constructor
         * @extends zrender/shape/Base
         */
var Trochoid = function (options) {
    this.brushTypeOnly = 'stroke';
    // 线条只能描边，填充后果自负
    Base.call(this, options);    /**
             * 内外旋轮曲线绘制样式
             * @name module:zrender/shape/Trochold#style
             * @type {module:zrender/shape/Trochold~ITrocholdStyle}
             */
                                 /**
             * 内外旋轮曲线高亮绘制样式
             * @name module:zrender/shape/Trochold#highlightStyle
             * @type {module:zrender/shape/Trochold~ITrocholdStyle}
             */
};
Trochoid.prototype = {
    type: 'trochoid',
    /**
             * 创建内外旋轮曲线路径
             * @param {CanvasRenderingContext2D} ctx
             * @param {module:zrender/shape/Trochold~ITrocholdStyle} style
             */
    buildPath: function (ctx, style) {
        var _x1;
        var _y1;
        var _x2;
        var _y2;
        var _R = style.r;
        var _r = style.r0;
        var _d = style.d;
        var _offsetX = style.x;
        var _offsetY = style.y;
        var _delta = style.location == 'out' ? 1 : -1;
        var _math = require('../tool/math');
        if (style.location && _R <= _r) {
            alert('参数错误');
            return;
        }
        var _num = 0;
        var i = 1;
        var _theta;
        _x1 = (_R + _delta * _r) * _math.cos(0) - _delta * _d * _math.cos(0) + _offsetX;
        _y1 = (_R + _delta * _r) * _math.sin(0) - _d * _math.sin(0) + _offsetY;
        ctx.moveTo(_x1, _y1);
        // 计算结束时的i
        do {
            _num++;
        } while (_r * _num % (_R + _delta * _r) !== 0);
        do {
            _theta = Math.PI / 180 * i;
            _x2 = (_R + _delta * _r) * _math.cos(_theta) - _delta * _d * _math.cos((_R / _r + _delta) * _theta) + _offsetX;
            _y2 = (_R + _delta * _r) * _math.sin(_theta) - _d * _math.sin((_R / _r + _delta) * _theta) + _offsetY;
            ctx.lineTo(_x2, _y2);
            i++;
        } while (i <= _r * _num / (_R + _delta * _r) * 360);
    },
    /**
             * 返回内外旋轮曲线包围盒矩形
             * @param {module:zrender/shape/Trochold~ITrocholdStyle} style
             * @return {module:zrender/shape/Base~IBoundingRect}
             */
    getRect: function (style) {
        if (style.__rect) {
            return style.__rect;
        }
        var _R = style.r;
        var _r = style.r0;
        var _d = style.d;
        var _delta = style.location == 'out' ? 1 : -1;
        var _s = _R + _d + _delta * _r;
        var _offsetX = style.x;
        var _offsetY = style.y;
        var lineWidth;
        if (style.brushType == 'stroke' || style.brushType == 'fill') {
            lineWidth = style.lineWidth || 1;
        } else {
            lineWidth = 0;
        }
        style.__rect = {
            x: -_s - lineWidth + _offsetX,
            y: -_s - lineWidth + _offsetY,
            width: 2 * _s + 2 * lineWidth,
            height: 2 * _s + 2 * lineWidth
        };
        return style.__rect;
    }
};
require('../tool/util').inherits(Trochoid, Base);
module.exports = Trochoid || module.exports;;